Adjustable phase two shaft vibrator

ABSTRACT

A vibrating mechanism for a two-shaft screen. Eccentric shafts are supported by bearings in the side plates of the screen frame or in mounts above or below the side plates. Each shaft has a coaxial torque tube to which it is connected by a flexible elastic coupling. The torque tubes are interconnected by meshing gears. One of the eccentric shafts has a sheave for a drive belt. The flexible elastic couplings permit the shafts to be rotatably adjusted relative to their torque tubes while the screen is stopped. When the screen is started up again, the forces due to the eccentricity of the two shafts bear a new phase relationship. This results in a new direction for the reciprocating motion of the screen.

United States Patent Marks [451 Dec. 5, 1972 [54] ADJUSTABLE PHASE TWOSHAFT Inventor:

Assignee:

220 DD; 259/DIG. 42; 209/366, 366.5, 367

References Cited UNITED STATES PATENTS 11/1962 Westbrook ..259/DIG. 428/1964 Roder et a1 ..198/220 DB 4/ 1972 Peterson ..74/607 FOREIGNPATENTS OR APPLICATIONS 772,270 4/1957 Great Britain ..74/61 PrimaryExaminer-William F. ODea Assistant Examiner-Wesley S. Ratliff, Jr.Attorney-Howard T. Markey et a1.

[5 7] ABSTRACT A vibrating mechanism for a two-shaft screen. Eccentricshafts are supported by bearings in the side plates of the screen frameor in mounts above or below the side plates. Each shafthas a coaxialtorque tube to which itis connected by a flexible elastic coupling. Thetorque tubes are interconnected by meshing gears. One of the eccentricshafts has a sheave for a drive belt. The flexible elastic couplingspermit the shafts to be rotatably adjusted relative to their torquetubes while the screen is stopped. When the screen is started up again,the forces due to the eccentricity of the two shafts bear a new phaserelationship. This results in a new direction for the reciprocatingmotion of the screen.

7 Claims, 3 Drawing Figures PATENTEDHEB 1912 3.704 631 SHEET 1 OF 2 7 I.1. J /i 1 I ADJUSTABLE PHASE TWO SHAFT VIBRATOR SUMMARY OF THEINVENTION This invention is concerned with a two-shaft vibratingmechanism for a vibrating screen.

An object of this invention is a vibrating screen mechanism in which thescreen's direction of motion may be easily changed.

Another object is a vibrating screen of the two-shaft type in which theshafts are interconnected by flexible elastic couplings.

Another object is a vibrating screen of the type having two shafts inwhich the shafts may be rotatably adjusted relative to each other.

Other objects may be found in the following specification, claims anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated more orless diagrammatically in'the following drawings wherein:

FIG. 1 is a partial, sectional view of the vibrating mechanism of thisinvention mounted on the side plates of a vibrating screen;

FIG. 2 is a side, elevational view of a vibrating screen utilizing thevibrating mechanism of this invention; and

FIG. 3 is an enlarged partial cross-sectional view of one end of aneccentric shaft of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 2 shows a side elevation ofa vibrating screen 11. The vibrating screen includes a frame 13 havingside plates 15. The frame 13 is supported on springs 17 carried bypedestals 19. Screening surfaces, which are not shown, are supported bythe side plates through intermediate members, also not shown.

' Eccentric shafts 25 and 27 (FIG. 1), having separate and/or integraleccentric weights 29 and 31, extend transversely across the frame 13 andare respectively supported by two sets of bearings. 33 and 35 which areheld in the side plates 15. Shaft 25 extends outwardly beyond the sideplates 15 on both sides of the frame while shaft 27 extends outwardlybeyond a side plate on only one side of the frame. A drive sheave 37 isattached to one end of the shaft 25 outwardly of the frame 13.

Torque tubes, or sleeves, 39 and 41 are respectively mounted around andcoaxial to the portions of the shafts 25 and 27 which are locatedoutwardly of a side plate 15 of the frame 13. The torque tubes arerespectively mounted in bearings 43 and 45 supported by inner and outerside walls 47 and 49 of a housing 51 which is bolted to a side plate 15of the frame 13.

Each torque tube is connected to its respective shaft by a flexibleelastic coupling 55. The Dodge Corporation of Mishawaka, Indianamanufactures couplings of this type under the trade name PARA-FLEX.Gears 57 and 59 are attached respectively to the torque'tubes 39 and 41and mesh with each other to provide a driving connection between thetorque tubes.

The drawing of FIG. 3 shows in enlarged detail the eccentric shaft 27,its torque tube 41 and a flexible elastic coupling 55 connecting theshaft and the torque tube. Since the flexible elastic couplingconnecting the shaft 25 and its torque tube 39 is identical, only onewill be described in detail. The flexible coupling includes a flexibleelement which is fastened by bolted ring clamps 66 and 67 to a flange 69affixed to the shaft 27 and by bolted ring clamps 70 and 71 to a flange73 affixed to the torque tube 41. The inner ring clamps 66 and 70 havethreaded holes 75 and 77 respectively which receive and engage bolts 79which pass through aligned openings 81,83 and 85,87 in the outer ringsand flanges 67,69 and 71,73 respectively.

The use, operation and function of this invention are as follows:

The vibrating mechanism of this invention is intended for use with avibrating screen in which the vibrations of the screening surfaces movethe material from the feed end to the discharge end of the screen. Thevibrating mechanism of this invention permits easy adjustment of themagnitude and direction of forcing. In addition, the characteristicshape of the envelope of resultant forcing vectors through a cycle maybe easily adjusted. The forcing direction of the vibrator may be changedby rotating either shaft 25 or 27 relative to its respective torque tube39 or 41 to vary the alignment of the eccentric weights 29 and 31relative to each other. This can easily be accomplished in thisinvention by loosening the bolts 79 of the bolted ring clamps 66,67 ofthe flexible coupling 55, rotating the eccentric shaft relative to itstorque tube, and then retightening the bolts. The forcing characteristicshape may be changed by varying the relative magnitude of the eccentricweights 29 and 31. The forcing amplitude may be changed by increasing ordecreasing the eccentric weights 29 and 31 by the same proportion or bychanging the rotational speed.

The vibrating mechanism is drivenby a V belt (not shown) which isconnected to the drive sheave 37. Rotation of the sheave rotates theshaft 25 which in turn rotates its torque tube 39 through its flexiblecoupling 55. Rotation of the torque tube rotates spur gear 57 whichrotates spur gear 59in the opposite direction. The torque tube 41rotates with its spur gear 59 and in turn rotates eccentric shaft 27through its flexible coupling 55. Thus, the eccentric shafts 25 and 27are rotated in opposite directions. In common with conventionaltwo-shaft vibrators, the forces produced by the rotation of eccentricweights 29 and 31 on shafts 25 and 27 respectively are totally additivetwice and totally subtractive twice during each cycle for theconventional one-to-one gear ratio. This forcing yields an envelope ofresultant force vectors which is linear or elliptical and is inclinedtowards the discharge end of the screen. Unlike common two-shaftvibrators, the inclination of the forcing line or ellipse can be changedat will. This adjustment is easily accomplished by the previouslydescribed procedure for changing the angular position of either torquetube relative to the shaft which runs through it. By changing theforcing direction and hence the direction of screen motion, it ispossible to retain material on the screening surfaces longer or to movethe material through the screen faster.

The flexible coupling between each eccentric shaft and its torque tubereduces wear on the meshing gears 57 and 59. The flexible couplingsabsorb the deflections of the eccentric shafts and prevent thedeflections from loading the torque tubes thereby allowing the torquetubes to maintain proper gear alignments.

manna 0011 In this specification, the eccentric weights have been shownas formed integrally with their shafts. However, it should be understoodthat these weights may be made separate and attachable to theireccentric shafts so that the magnitude of the weights can be changed toalter the forcing characteristics of the vibrating mechanism. Also,although FIG. 2 shows the vibrator on the center of gravity of thescreen, it might be located elsewhere, for example, on the top or bottomof the screen.

Whereas, the preferred form of the invention has been described andshown, it should be understood that there are modifications, alterationsand changes which may be made without departing from the teachings ofthe invention. Therefore, the scope of the invention should be onlylimited by the claims attached hereto.

. I claim:

1. A vibrating mechanism for a vibrating screen including: a pair ofeccentric shafts,

a drive means attached to one end of one of said shafts, and

means connecting the opposite ends of said shafts to rotate said shaftsin unison,

said connecting means including:

a torque tube coaxially positioned over each shaft,

a gear attached to each torque tube and meshed with the gear of theother torque tube, and

a flexible coupling joining each torque tube and its respective shaft.

2. The vibrating mechanism of claim 1 further characterized in that saidflexible couplings are of the Inna elastic type. v

3. The vibrating mechanism of claim 1 further characterized in thatmeans are provided for rotating the shafts relative to their torquetubes.

4. A vibrating mechanism for a vibrating screen including:

a pair of eccentric shafts each supported on the side plates of a screenframe,

a drive means attached to one end of one of said shafts, and I meansconnecting the opposite ends of said shafts to rotate said shafts inunison,

said connecting means including means to advance or retard one eccentricshaft relative to the other to alter the forcing direction of thevibrating screen.

5. The vibrating mechanism of claim 4 further characterized in that saidconnecting means include:

a torque tube coaxially positioned over each shaft,

a gear attached to each torque tube and meshed with the gear of theother torque tube, and v a flexible coupling joining each torque tubeand its respective shaft.

6. The vibrating mechanism of claim 5 further characterized in that saidflexible couplings are of the elastic type.

7. The vibrating mechanism of claim 5 further characterized in that saidmeans to advance or retard one eccentric shaft relative to the otherincludes means to rotate said shaft relative to its torque tube.

1. A vibrating mechanism for a vibrating screen including: a pair ofeccentric shafts, a drive means attached to one end of one of saidshafts, and means connecting the opposite ends of said shafts to rotatesaid shafts in unison, said connecting means including: a torque tubecoaxially positioned over each shaft, a gear attached to each torquetube and meshed with the gear of the other torque tube, and a flexiblecoupling joining each torque tube and its respective shaft.
 2. Thevibrating mechanism of claim 1 further characterized in that saidflexible couplings are of the elastic type.
 3. The vibrating mechanismof claim 1 further characterized in that means are provided for rotatingthe shafts relative to their torque tubes.
 4. A vibrating mechanism fora vibrating screen including: a pair of eccentric shafts each supportedon the side plates of a screen frame, a drive means attached to one endof one of said shafts, and means connecting the opposite ends of saidshafts to rotate said shafts in unison, said connecting means includingmeans to advance or retard one eccentric shaft relative to the other toalter the forcing direction of the vibrating screen.
 5. The vibratingmechanism of claim 4 further characterized in that said connecting meansinclude: a torque tube coaxially positioned over each shaft, a gearattached to each torque tube and meshed with the gear of the othertorque tube, and a flexible coupling joining each torque tube and itsrespective shaft.
 6. The vibrating mechanism of claim 5 furthercharacterized in that said flexible couplings are of the elastic type.7. The vibrating mechanism of claim 5 further characterized in that saidmeans to advance or retard one eccentric shaft relative to the otherincludes means to rotate said shaft relative to its torque tube.